Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare a safe, idempotent read, so the bar is lower. The description adds real value beyond them: the authorization scope is limited to accounts this agent key may use, the status field is characterized as the control plane's last known value (i.e. possibly stale), and there is an explicit prompt-injection warning about {"untrusted_text": ...} fields.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences, front-loaded with the scope, then the sequencing instruction, then the security caveat — nothing redundant and every clause carries information an agent needs.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description compensates by naming the returned fields, and annotations cover the safety profile. Pagination or result-size behavior is unstated, a minor gap for a list endpoint.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool takes zero parameters, so per the rubric the baseline is 4. The description correctly signals a parameterless, list-everything call.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (List) and resource (MT4/MT5 trading accounts) plus the authorization scope ('this agent key may use'), and enumerates the returned fields (account_id, platform, broker server, login, status). It is clearly distinguishable from siblings like get_account_info or get_account_health, which target a single account.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

'Call this first to get account ids' gives explicit sequencing guidance that routes the agent here before per-account tools. It does not state when *not* to use it or name an alternative, so it falls just short of a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.